Abstract

Light fastness of thermochromic colorants, which shows reversible change in color with temperature, is of great importance for different textile and non-textile application. Light fastness of commercial thermochromic colorants was determined by measuring the color strength (K/S) of cotton fabric dyed with thermochromic colorants at regular intervals after exposure in Xenon Arc Light fastness tester and found to be poor for any application. An attempt to improve the light fastness of thermochromic colorant was made by using two ultraviolet absorbers (UVA) and two Hindered Amine Light Stabilizer (HALS) individually and in combination as additives in dye-bath formulation. UV absorbers showed better performance than HALS in terms of photostabilization. Significant improvement of photostability was observed when UV absorber and HALS were used in combination.